There are more babies born on 27 September than any other day of the year. In fact, an average of 1,993 people are born on this date in the UK each year, according to figures from the Office for National Statistics.
With the school year starting in September, September babies will often be the oldest in their class - but does this also mean they are likely to get the top grades?
A study from 2023 found that September babies tend to be more successful, with grades of students born in September aged between six and 15 often higher than their peers.
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The research from the National Bureau of Economic Research found that people born in September were more likely to have higher overall test scores, less likely to go to jail, and more likely to be accepted into top schools.
A separate study from 2011 of 48,500 children and teenagers in England found that children born in August were 20% less likely to go to top universities compared with those born in September, and were more likely to exhibit lower socio-emotional development.
The research showed that those born at the end of the academic year were also more likely to have lower confidence in their academic ability.
"As an educator, I've observed that being born in September can provide a child with a potential academic advantage during the Early and Primary Years of school," parenting expert Danielle Baron tells Yahoo UK.
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"However, it's important to note that research suggests that children tend to catch up as they progress through their educational journey. Beyond the temporal advantage, there exists a psychological expectation among parents and teachers that the oldest child in the class will perform better, and studies indicate that these expectations alone can significantly influence outcomes, further fostering a child's development."
The ‘relative age effect’
Baron says that the academic impact of a child’s birth month, especially when comparing students born in September to those born in July or August, is a phenomenon often referred to as the 'relative age effect'.
"[It] is primarily due to the cut-off dates for school enrolment and grade placement in various educational systems," she adds.
"In many countries, the school enrolment cut-off date typically falls around September. Consequently, children born in September often commence their educational journey at a slightly older age than their counterparts born in July, who may find themselves among the youngest in their class. This difference in starting age can lead to varying levels of physical, emotional, and cognitive development between these two groups."
Baron adds that some psychological factors can come into play, as being the oldest in the class can "influence a child’s self-esteem and perceptions of their own academic capabilities".
"Older students might exhibit higher confidence levels, while younger ones may grapple with self-doubt or feelings of academic inadequacy," she adds.
However, this doesn’t mean that children born at the end of the academic year cannot succeed - Rishi Sunak and Boris Johnson were born in May and June respectively.
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"It's vital to emphasise that these effects are not deterministic and can vary significantly from one individual to another," Baron adds.
"Some children born in September may excel academically, while others born in July may also perform exceptionally well."
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